河南省遂平县781铀矿矿山地质环境治理及意义

根据781铀矿存在的主要地质环境问题及危害程度现状分析、提出工程措施和生物措施相结合的治理方案,从而消除了铀矿渣核辐射威胁,恢复了矿区生态环境,改善了矿区及附近居民的生存、生活环境,结果表明：通过治理前后水样及矿渣堆放射性测量结果对比、治理后的矿渣堆积区的各种测试值均相对治理前大幅度降低。说明方案科学、可靠、治理效果明显。     

余姚市严格废弃矿山治理工程管理加强廉政风险防控

为加快推进涉及四边三化、森林城市创建、高速沿线重点废弃矿山在内的年度67家废弃矿山治理．余姚市局积极落实三项措施。进一步加强废弃矿山生态治理工程管理,切实规避废矿治理工程领域廉政风险。一、规范项目招标行为。一是扩大投标单位范围。允许原来确定的9家《治理方案》涉及单位候选名单以外的单位参加设计招标;允许原来确定的22家治理施工入围名单以外的单位参加废弃矿山治理工程招标。     

安徽某铁矿排土场废矿石中细菌群落分子生态学研究

采集了安徽某铁矿排土场酸水库周边不同类型的废矿石样品,分析了样品的物理化学性质,进而用分子生物学方法对比研究了样品中嗜酸菌群落组成及物理化学参数对群落结构的影响。结果表明,所采4个废矿石样品均呈强酸性,pHKCl均在3.0以下,并含有大量的金属离子和硫酸根阴离子,而有机质含量很低。总的来说,风化废矿石样品（KB和PD）比根际样品（WJ和GY）的物理化学条件更为严酷。样品中的细菌分属15个细菌类群,其中7个类群在4个样品中都有分布。经聚类分析发现,无论是物理化学参数还是细菌群落组成,都是风化废矿石样品聚为一个分枝,而根际样品聚为另一个分枝,说明物理化学条件对细菌群落组成有着决定性的影响。4个样品的Shannon指数和Simpson指数均显示,根际废矿石样品比风化废矿石样品细菌多样性高。各种物理化学参数对样品细菌群落的多样性影响不一样,pH和有机质含量与细菌多样性呈正相关关系,而硫酸根和磷与细菌多样性呈负相关关系。酸杆菌门细菌在所有4个样品中都占有很高的比例,它们在废矿石生态系统的物质循环和能量流动中发挥着重要的作用。     

铜陵矿区废矿石次生氧化产物及其成因初探

对铜陵矿区废矿石的矿物组成及其成因进行研究,利用X射线衍射仪（XRD）和扫描电子显微镜（SEM）分析原生矿物及其风化产物的组成,探讨次生矿物的形成机制。XRD及SEM/EDS分析表明,废矿石中残留的主要原生矿物为黄铁矿,次生矿物为针铁矿、赤铁矿、水铁矿及次生硫酸盐矿物。原生矿物风化为次生矿物的过程是从黄铁矿的裂隙带等有缺陷的部位开始,逐步氧化成最终产物针铁矿。中间过程出现了矿物相及形态的多样性,局部可能会先形成中间产物水铁矿,由于水铁矿很不稳定,在不同的温、湿度条件下会很快转化成针铁矿或赤铁矿。针铁矿在风化过程中呈现出多种形态,针状矿物最先形成,随后重结晶成球状集合体和菱方双锥单晶,最后在废矿石表面完全覆盖一层土状针铁矿。SEM观察到的黄铁矿表面的生物矿物与最外层风化层上的菌丝类物质说明,在废矿石的风化过程中生物亦起了一定的作用。     

湘中桃江锰矿废矿堆环境地球化学分析

对湘中桃江锰矿废矿堆的废石进行了主量元素、稀土元素、微量元素和重金属元素的地球化学分析。野外观察及分析结果表明:组成废矿堆的岩石主要是赋矿围岩中奥陶统黑色页岩和原生碳酸锰矿石。这些废石富含Cu、Pb、Zn、Cr、Tl、Sb、U等重金属元素。废石暴露地表而遭受风化分解,导致Sc、V、Cr、U、Cd、Th等重金属元素淋滤释出,在废石样品中均表现出不同程度的迁移特征,且以V、Cd、U的迁移性最为强烈。此外,黑色页岩中Ni、Cu、Zn、Pb、Tl、Sb也明显发生淋失。这些重金属元素如Cd、Tl等毒性极强,进入矿区周围不断积聚,便可能对环境造成严重的影响。故对区内分布的废矿堆作为重金属污染源应高度重视。     

铜陵鸡冠山硫铁矿废矿堆积区的重金属分布与磁化率变化

应用ICP-AES、EMPA和矿物磁测,对铜陵市鸡冠山硫铁矿废矿堆积区的废矿及周围进行系统分析.发现不同堆放时间的废矿样品中重金属含量的变化规律不同,在堆放时间为10年和6年的剖面(分别为XO、XM剖面)呈现富集-淋滤-富集的变化模式,而在堆放时间<3年的剖面(XN剖面)呈现富集-淋滤的变化模式.结合重金属迁移的特性,证明重金属对周边的生态环境存在着潜在的危害性.同时还分析了风化程度不同的XO、XM、XN剖面样品中磁化率与重金属的关系,证实两者之间存在较好的相关性.磁化率是重金属含量变化的一个有效指数,它的研究为重金属污染研究提供了一个新的方法.     

马槽沟泥石流工程治理及效益分析

本文对马槽沟泥石流成因、特征、危害、治理方案、工程设计及治理效益进行了分析研究。该工程建成已运行八年,泥石流危害现已基本解除,治理工程产生了良好的减灾效益、经济效益和社会效益。     

废弃露天矿坑作为卫生填地目的的岩土调查

位于俄亥俄州东北部的五个露天矿场地被选出以调查它们作为卫生填地的适宜性。以作为表面覆盖物和衬料为目的,对每个场地的废矿石的工程特性进行了研究,详细的调查旨在评价每个场地的地质和水文地质条件。废矿石一般被定为低塑性、分选良好的含细粒砂,室內密度范围为1.59～1.99g/cm~3,相应未击实废矿石原位密度值范围为1.20～1.90g/cm~3,密度—渗透系数曲线表明作为覆盖物渗透系数(1×10~(-5)cm/sec)在相对击实性约为90％时能够达到,而作为衬料的渗透系数(1×10~(-7)cm/sec)在某些废矿石的相对击实性达到95％以上能够达到。击实到最大干密度和具有最优含水量湿度的废矿石渗透系数值范围在2.5×10~(-7)～5.6×10~(-8)cm/sec,而野外的渗入试验得到渗透系数范围在5×10~(-3)～5×10~(-7)7cm/sec间,原位试验含水量值常比最优含水量值偏大。抗崩解持久性指数范围在54.6～97.7,这表明废矿石中页岩具有中等到很强的抗崩解性.废矿石的工程特性表明它们作为覆盖物是很适宜的,但作为衬料却只有极小的合格率。页岩是场地下伏的主要岩石类型,能够大大增加场地作为卫生填地的适宜性的底粘土出现于其中的三个场地。一般地,在场地下面紧挨部位,没有发现明显的含水层组。大部分水补给是从地面以下并且被粘土和页岩与表面开采活动的水文地质条件上分离,这些调查表明,从环境方面考虑,这些工程上废弃的露天矿坑可以很好地用于卫生填地。     

贵州省安龙县戈塘镇大海子岩溶洪涝的治理及其工程意义

贵州岩溶石山区岩溶洪涝洼地发育、内涝灾害造成了大量的耕地破。查明洪涝洼地成因并有效进行治理,对防灾减灾、生态环境治理、促进石山区经济社会发展具有重大意义。本文阐述了大海子岩溶洪涝的特征及其危害,探讨了洪涝洼地的成因,有针对性地提了治理方案。可为同类型治理工程提供借鉴。     

地质灾害治理的产业化分析

我国地质灾害种类多、分布广、危害大、形势严峻。本文通过分析地质灾害治理中的外部性、产权及其治理机制,指出至少有天灾、历史遗留欠账、治理主体难以明确的共三类地质灾害的治理是需要国家财政负担。本文提出,针对这三个类型的地质灾害治理,通过对地质灾害发生地的土地、矿产和地质资源创建产权,并与地质灾害治理捆绑出让,获得地质灾害的长效治理,最后提出了若干建议。     

Analyses and settlement study of a group of two,three and four partially stiffened floating granular piles

ABSTRACT

Use of granular pile as a ground improvement technique in case of soft soils is one of the reliable and economic options. Analysis of a partially stiffened group of granular floating piles has been numerically assessed and presented here. Partial stiffening simply means that instead of using conventional material for making the granular pile (GP) in its full length, top region is replaced partially by some suitable material, having better mechanical properties, i.e. higher deformation modulus. Various normalised parameters like settlement influence factor for top of GP, settlement interaction factor, settlement reduction factor, percentage load shared by the base and shear stress distribution along the length of the granular pile are evaluated. The settlement influence factor for top of GP is found to decrease with the increase in the values of the stiffening parameters. The interfacial shear stresses get redistributed along the length of the granular pile.     

Land subsidence in Bangkok, Thailand

Land subsidence from deep well pumping has been affecting Bangkok for the past 35 years. Its impact is particularly critical because of the flat low-lying topography and the presence of a thick soft clay layer at the ground surface that augment flood risk and foundation engineering problems, respectively. The subsidence reached its most critical state in the early 1980s when it occurred at a rate as high as 120 mm/year. The rate decreased in the subsequent period but the subsidence-affected area expanded following the growth of the city. Despite various attempts implemented to remedy the crisis, groundwater pumping from the thick aquifer system underneath the city continued to increase from 1.2 million m³/day in the early 1980s to more than 2.0 million m³/day at the turn of the century. Piezometric levels in the main aquifer layers had been drawn down by as much as 65 m. Monitoring data showed a clear correlation between the subsidence and piezometric drawdown. The data suggested that for 1 m³ of groundwater pumped out in Bangkok Plain, approximately 0.10 m³ of ground loss occurred at the surface. Significant development has been made in numerical methods for prediction of differential settlements between building foundations caused by the piezometric drawdown in the aquifers. The strict mitigation measures adopted recently, comprising a pricing policy for groundwater management, an expansion of tap water supply, and strict enforcement of groundwater laws, have resulted in a marked drop in groundwater use. However, the land subsidence will continue for a long while owing to the time-dependent consolidation behavior of the soft clay layer and clay aquitards.     

填石路堤变形观测方案设计与实施

本文介绍了“西部项目”中现场试验路段填石路堤变形观测的设计和实施过程;针对填石路堤进行沉降观测存在的问题与监测中所采用的观测方法和设备进行了讨论,并对其设计及实施过程进行了研究。观测结果分析表明,所提出的实施方案及观测方法可行,结果可靠,对填石路堤变形观测工作有一定的实用价值。      

贵州喀斯特聚落文化类型及其特征研究

从喀斯特环境人地关系的角度出发,探讨贵州喀斯特聚落文化的组成因子和文化层;依据地域分异规律、相似性原则、综合分析原则,将贵州喀斯特聚落文化分为谷地聚落、半坡村聚落、溪边村聚落、丘原区聚落、洞穴聚落和屯堡聚落六种主要类型。谷地聚落因峰丛洼地环境容量小,形成散珠状小聚居的形态和独特的垦殖文化景观;半坡村聚落因喀斯特山地环境的影响,形成依山而建、聚族而居、典型的吊脚楼民居建筑等特征;溪边村聚落因峰林坝地环境容量较大,沿河形成串珠状聚族而居的形态;丘原区聚落因丘原盆地环境容量大、地域环境开放,形成多民族杂居、村寨密集分布、文化交融强等特征;洞穴聚落因岩洞环境的特殊性,形成依洞而建的小聚居形态;屯堡聚落因喀斯特环境和历史的影响,形成典型的集聚型村落,将石文化、江南文化、军事文化有机结合。通过探讨各类型聚落文化在聚落规模、聚落布局、聚落环境、建筑、生活习俗等方面的特征,可为合理开发贵州喀斯特聚落文化提供依据。      

Consolidation analysis of a cross-anisotropic homogeneous elastic soil using a finite layer numerical method

This paper presents a finite layer procedure for Biot's consolidation analysis of layered soils using a cross-anisotropic elastic constitutive model. The program is first verified using published results. Then, using this program, the influences of cross-anisotropy on the immediate settlement, the final settlement, and the consolidation behaviour are investigated by changing one model parameter at one time. The results obtained using the cross-anisotropic elastic model are compared with results using an isotropic elastic model. It is found that the cross-anisotropy has very large influences on the immediate settlement, the final settlement, and the consolidation behaviour. Curves or tables of the immediate settlement coefficients, the final settlement coefficients, and the average degree of consolidation are obtained and presented in the paper. These curves or tables can be easily used to estimate the immediate settlement, the final settlement, and the consolidation settlement of a cross-anisotropic soil. Copyright © 2004 John Wiley & Sons, Ltd.     

高速公路扩建工程软基拓宽的沉降监测与分析

高速公路拓宽建设中新老路基特别是软土路基的固结沉降与力学性质的差异将引起严重的路面开裂,因而控制其差异沉降、防止拼接处路面开裂成为扩建工程软基处理中的技术关键。针对采用薄壁管桩和粉喷桩处理的软基路段,选取具有典型地质条件及较高填方的断面,通过埋设地面沉降板,对拓宽路基及新老路堤结合部进行了为期9个月的沉降动态监测。监测结果表明,拓宽路基的累计沉降及差异沉降均很小,后期沉降速率小于控制标准,为新老路基差异沉降的评价提供了依据;薄壁管桩用于处理埋深大、层厚大的拓宽软基及粉喷桩用于处理埋深浅、层厚较小的拓宽软基具有各自的适用性,拓宽后的新老路基已形成整体性强的复合地基,达到了路基拓宽的理想效果。     

Reconstruction of fluvio-lacustrine landscapes and settlement history in the Texcoco region,Mexico, using a modern geomorphic analog

Located in the Basin of Mexico, the eastern shore of former Lake Texcoco sustained a variety of human occupations throughout the Holocene, including preceramic hunter-gatherers, incipient agriculturalists, and a variety of settlements in the ceramic periods. Nonetheless, the environmental dynamics of occupations on the lakeshore have not been fully addressed. The Archaic preagricultural Texcoco Man site (>5000 B.C.E.) and the Late Formative TX-LF-14 site (c. 550-200 B.C.E.), among others, occupy this fluvio-lacustrine transitional environment. Few stratigraphic works in and around the sites have been performed. Consequently, it is difficult to understand the dynamics of the sedimentary system in space and time. This work highlights and describes the fluvio-lacustrine sedimentary dynamics and the resulting landscape that past societies inhabited on the eastern shore of Texcoco Lake. Because the study area has been altered by historic and modern draining, our work employs Lake Santiaguillo and its main tributary, the Tejamen River in the Durango state, as a modern analog to study their sedimentary dynamics. The analyses of surface geomorphology in the Texcoco study area were employed to corroborate the modern analog interpretation. To achieve these goals, we conducted a GIS-based morphometric analysis and LANDSAT-8 imagery to study the variations in landforms through wet and dry events. The results indicate an increase in the lake volume, low bifurcation in the active fluvial channels, few inundated surfaces, and the presence of bird-foot deltaic channels during high precipitation events. In contrast, low precipitation events are characterized by reduced lake volume, increased fluvial channel bifurcation, and expanded floodplains. This heterogeneous landscape thus provided a rich source of diverse natural resources of saline and freshwater aquatic habitats. Simultaneously, constant or recurring flooding events generated a challenging landscape for prehistoric settlers who implemented diverse technologies, such as the construction of tlateles, on the levees of deltaic channels to reduce the risk and impact of flooding events.     

Peck公式在我国隧道施工地面变形预测中的适用性分析

在目前众多的预测地铁隧道开挖引起的地表位移的经验方法中，Peck于1969年提出的高斯方程最简便，也是目前应用最为广泛的方法。由于这一公式是基于有限地区的实测资料提出的，因此，在某个地区应用前首先应该进行基于当地实测资料的验证工作。国内地铁建设工作起步相对较晚，在土中开挖的浅埋隧道工程引起的地层变形实测资料比较缺乏，因此，目前对Peck公式在国内各地区的适用性还没有定论。近年来，随着地铁建设热潮的兴起，各地逐渐积累了一些实测资料，但仍比较零散，也没有形成比较统一的结论。通过对搜集到的国内8个地区30多组观测数据的分析，评价这一方法在不同地区的适用性，并对相关计算参数提出初步建议值。     

软土地基沉降速率的分析研究及其应用

本文利用Terzaghi一维固结理论推导出了在主固结阶段沉降速率与沉降、剩余沉降及固结时间的关系。结果表明，沉降速率与沉降、剩余沉降均呈线性关系，沉降速率的对数与固结时间成正比。根据这些函数关系，就可推算出最终主固结沉降、剩余沉降以及固结时间，为工程施工提供理论依据。本文还结合了工程实例，论证其可行性。     

基于振动碾压下沉量对比的一种珊瑚砂次压缩系数推测方法

工程中对于工后沉降的预测有重要的实际意义,而次压缩系数是工后沉降预测的关键参数。对于吹填珊瑚砂采取原状土样进行室内试验确定其次压缩系数是一个难题。提出了基于振动碾压下沉量对比反演推测珊瑚砂次压缩系数方法并给出了计算实例,该法通过查询老吹填场地的历史吹填时间,对比振动碾压地基处理试验过程中新吹填试验区和老吹填试验区的地表沉降量,对珊瑚砂次压缩系数进行反演推测。同时对影响反演推测结果的因素进行了分析。